Autologous wound sealing apparatus

ABSTRACT

The apparatus is provided for sealing a vascular puncture tract by forming the autologous plug within the puncture tract, and extruding that plug into the puncture tract. The apparatus of the present invention forms an autologous blood plug by drawing blood into the apparatus from a vessel, mixing a blood congealing agent with the drawn blood, and ejecting a plug formed from the clotted blood within the puncture tract. Also provided are various closure elements to isolate the drawn blood from the vessel during mixture with the blood congealing agent, and to facilitate placement of the apparatus relative to the vessel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. patent application Ser. No.10/523,219, filed 19 Oct. 2005, which is a 371 Nationalization ofPCT/EP2003/008246, filed 25 Jul. 2003, which claims the benefit of andpriority to U.S. Provisional Patent Application Ser. No. 60/401,226,filed 1 Aug. 2002, the disclosures of which are incorporated herein bythis reference.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates to apparatus for sealing puncture tracts.More specifically, the invention relates to apparatus that seals apuncture tract by forming and extruding an autologous plug therein.

2. The Background of the Invention

A large number of medical diagnostic and therapeutic procedures involvethe percutaneous introduction of instrumentation into the blood vessel.For example, coronary angioplasty, angiography, atherectomy, stenting,and numerous other procedures often involve accessing the vasculaturethrough placement of a catheter or other device in a patient's femoralartery or other blood vessel. Once the procedure is completed and thecatheter or other diagnostic or therapeutic device is removed, bleedingfrom the resultant vascular puncture must be stopped.

Traditionally, a medical practitioner applies external pressure to thepuncture site to stem bleeding until hemostasis occurs (i.e. when theclotting and tissue rebuilding have sealed the puncture). This method,however, presents numerous problems. In some instances, this pressuremust be applied for up to an hour or more, during which time the patientis uncomfortably immobilized. In addition, there exists a risk ofhematoma since bleeding from the puncture may continue until sufficientclotting occurs, particularly if the patient moves during the clottingprocess. Furthermore, application of external pressure to stop bleedingmay be unsuitable for patients with substantial amounts of subcutaneousadipose tissue since the skin surface may be a considerable distancefrom the puncture site, thereby rendering external compression lesseffective.

Another traditional approach to subcutaneous puncture closure compriseshaving a medical practitioner internally suture the vessel puncture.This method, however, often requires a complex procedure and requiresconsiderable skill by the medical practitioner.

Mechanical occlusion devices have been proposed for sealing, e.g.,atrial septal defects, and typically comprise two expandable disks thatsealingly compress tissue surrounding the hole. One such device isdescribed in U.S. Pat. No. 5,425,744 to Fagan et al. A significantdrawback to the Fagan device is that, when deployed into a vessel, thedevice may protrude into the blood stream, thereby disturbing blood flowand causing thrombosis in the vessel.

Apparatus and methods also are known in which a plug is introduced intothe vessel puncture, to cover the puncture and promote hemostasis.Various types of plugs have been proposed. One example is described inU.S. Pat. No. 5,061,274 to Kensey, comprising a plug made fromanimal-derived collagen. Such apparatus may be unsuitable for somepatients due to an adverse immunological reaction to animal-derivedcollagen, which could lead to anaphylactic shock.

U.S. Pat. No. 6,159,232 to Nowakowski describes an apparatussubstantially disposed outside a patient's body that activates aclotting cascade within blood, and then introduces the treated blood tothe wound site to complete clotting and promote hemostasis.Disadvantageously, the apparatus described in that patent comprises amultiplicity of primarily standard, off-the-shelf components that amedical practitioner would have to assemble prior to use. This greatlyis complicates the procedure, and increases opportunities for humanerror and contamination. Furthermore, the apparatus resulting from theassembly of the numerous individual components may be unwieldy to useand expensive.

In view of these drawbacks, it would be desirable to provide apparatusfor sealing a puncture tract by forming and extruding an autologous plugwithin the puncture tract.

It also would be desirable to provide apparatus for sealing a puncturetract that are easy to use, and decrease opportunities for error andcontamination.

It further would be desirable to provide apparatus for sealing apuncture tract that facilitate placement of the apparatus relative to avessel.

It still further would be desirable to provide apparatus for sealing apuncture tract that prevent leakage of blood congealing agents into avessel during delivery thereof.

BRIEF SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the present invention toprovide apparatus for sealing a puncture tract by forming and extrudingan autologous plug within the puncture tract.

It also is an object of the present invention to provide apparatus forsealing a puncture tract that are easy to use, and decreaseopportunities for error and contamination.

It further is an object of the present invention to provide apparatusfor sealing a puncture tract that facilitate placement of the apparatusrelative to a vessel.

It even further is an object of the present invention to provideapparatus for sealing a puncture tract that prevent leakage of bloodcongealing agents into a vessel during delivery thereof.

These and other objects of the present invention are accomplished byproviding apparatus for sealing a puncture tract by forming andextruding an autologous plug within the puncture tract. Morespecifically, the apparatus of the present invention forms theautologous plug by drawing blood into the apparatus from a vessel influid communication with the puncture tract, and supplying a bloodcongealing agent to the drawn blood. Consequently, a plug of clottedblood forms within the apparatus, which then may be extruded out of theapparatus and disposed along at least a portion of the length of thepuncture tract.

In a preferred embodiment, the apparatus of the present inventioncomprises a housing dimensioned to be inserted at least partially intothe puncture tract. The housing comprises inner and outer tubes thatdefine an annular lumen. The inner tube comprises a central lumen inwhich an autologous plug is formed that is then extruded to occlude thepuncture tract. The device also comprises a plunger slidably disposedwithin the central lumen to facilitate drawing blood from the vesselinto the central lumen, and extruding the plug from the central lumeninto the puncture tract. In alternative embodiments, the annular lumenand/or the outer tube may be omitted.

To isolate a mixture of blood and blood congealing agent from the vesselduring formation of the autologous plug, the device further comprises aclosure element, such as a pledget, an iris closure, an alignmentclosure, or a membrane that is permeable to blood but impermeable to theblood congealing agent.

To initiate clotting of the drawn blood within the central lumen, ablood congealing agent, such as, e.g., thrombin, fibrin or human factorVIII, may be introduced thereto by injection from an external source, orby pre-coating the central lumen. Alternatively, the central lumen maybe lined or pre-loaded with a matrix that is preferably biodegradable,e.g., gauze, bio-compatible foam or spun fiber, or platinum orthermo-resistive wires may be disposed within the wall of the inner tubefor contact with the blood therein.

Disposition of the autologous plug formed from the coagulated blood intothe puncture tract seals the puncture tract and vessel from leakage. Thetissue surrounding the puncture tract compressively engages theautologous plug along its length, generating frictional forces thatprevent the plug from becoming dislodged into the vessel. These andother objects and features of the present invention will become morefully apparent from the following description and appended claims, ormay be learned by the practice of the invention as set forthhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features of the present invention, its nature and variousadvantages will be more apparent from the accompanying drawings and thefollowing detailed description of the preferred embodiments, in which:

FIG. 1 is a schematic side-sectional view of a vascular puncture tract;

FIG. 2 is a schematic perspective view of is apparatus of the presentinvention;

FIG. 3 is a schematic side-sectional view of the apparatus of FIG. 2;

FIGS. 4A-4E are schematic side-sectional views describing an exemplarymethod of using the apparatus of FIGS. 2 and 3;

FIGS. 5A-5E are schematic side-sectional and end views of alternativeembodiments of apparatus of the present invention;

FIG. 6 is a schematic side-sectional view of another alternativeembodiment of the apparatus of the present invention;

FIGS. 7A and 7B are, respectively, a schematic exploded perspective viewand a schematic side-sectional view of an iris closure of the apparatusof FIG. 6;

FIG. 8A-8C are schematic plane views of an inner tube and the irisclosure, respectively, of the apparatus of FIGS. 6 and 7;

FIGS. 9A-9D are schematic side-sectional views describing an exemplarymethod of using the apparatus of FIGS. 6-8;

FIGS. 10A and 10B are schematic side-sectional views of alternativeembodiments of the apparatus of FIGS. 6-9;

FIG. 11 is a schematic side-sectional view of a still further embodimentof the apparatus of the present invention;

FIGS. 12A and 12B are schematic cross-sectional views of an alignmentclosure of the apparatus of FIG. 11; and

FIGS. 13A and 13B are, respectively, a schematic side-sectional view anda schematic end view of yet another alternative embodiment of theapparatus of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Upon completion of a medical diagnostic or therapeutic procedureinvolving percutaneous introduction of instrumentation into blood vesselV, removal of the instrumentation from the patient leaves puncture tractTR. As seen in FIG. 1, puncture tract TR extends through subcutaneoustissue T and terminates at puncture P. The apparatus of the presentinvention is directed to a device for sealing puncture tract TR byfacilitating formation and disposition of an autologous plug within thepuncture tract. More specifically, the apparatus facilitates formationof the plug by drawing blood into a lumen of the apparatus, andproviding a blood congealing agent to the blood therein, which causesthe blood to clot and form an autologous plug within the lumen. Theautologous plug is extruded from the lumen to seal puncture tract TR,thereby sealing vessel V from blood leakage.

An illustrative embodiment of device 10 of the present invention isshown in FIGS. 2 and 3. Device 10 comprises housing 12 having manifold14, injection port 16, and distal opening 18, plunger 20 having head 21and shank 23 disposed for axial translation within housing 12, andpledget 22. Pledget 22 may be disposed within and is removably coupledto housing 12. As described in greater detail hereinbelow, fluidcommunication between distal opening 18 and injection port 16 permits amedical practitioner to easily determine when device 10 has beenadvanced is within puncture tract TR to a position just proximal tovessel V.

Housing 12 further comprises inner tube 24 and outer tube 28, which maybe distally tapered to provide an atraumatic bumper for advancement ofdevice 10 through puncture tract TR, or may be distally angled for flushalignment with an angled puncture tract TR, such as the puncture tractof FIG. 1. Inner and outer tubes 24 and 28 form annular lumen 30, whichis in fluid communication with manifold 14 and injection port 16.Annular lumen 30 extends along the length of inner tube 24 and is influid communication with central lumen 26, via plurality of apertures32. Apertures 32 are disposed through and along the axial length ofinner tube 24. Optional gap 34 is defined between the distal ends ofinner and outer tubes 24 and 28.

Fluid communication between injection port 16 and central lumen 26permits a blood congealing agent to be injected through injection port16, e.g., a luer valve, into blood drawn within central lumen 26.Mixture and chemical interaction between the blood congealing agent,e.g., thrombin, fibrin and/or human factor VIII, and the blood initiatesa clotting reaction that congeals the blood into an autologous plug. Theplug is extruded from central lumen 26 into puncture tract TR to sealthe vessel puncture.

In a preferred embodiment, central lumen 26 has a diameter equal to thatof distal opening 18. Once an autologous plug is formed within centrallumen 26, it is extruded into puncture tract TR, where the plug engagescompliant tissue T surrounding the puncture tract along its length,thereby retaining the plug within the puncture tract. Engagement betweenthe is plug and tissue may be increased by enlarging the diameter ofcentral lumen 26 and distal opening 18, thereby permitting an increasein the diameter and surface area of the autologous plug that is formedand extruded. The diameter of shank 23 of plunger 20 is selected so thatshank 23 may be translated within central lumen 26, yet prevents bloodleakage around proximal opening 36 of central lumen 26.

As shown in FIGS. 2 and 3, the diameter of central lumen 26 also isdimensioned to permit thread 38 to be translatably disposed betweenplunger 20 and inner tube 24. Alternatively, plunger 20 may be providedwith a thread lumen (not shown) through which thread 38 may betranslatably disposed. Thread 38 exits housing 12 through proximalopening 36, and is distally attached to loop 40 of pledget 22. Pledget22 includes disk 42, to which loop 40 is coupled, preferably rigidly.

In a preferred embodiment, disk 42 is elliptically shaped, and has majorand minor axes that permit disk 42 to completely cover puncture P whendisposed therein. Accordingly, when pledget 22 is engaged to the innerwall of vessel V within puncture p, immediate hemostasis may beachieved. If the minor axis of disk 42 is greater than the diameter ofcentral lumen 26, disk 42 may be made of a material that permits disk 42to be elastically deformed to fit within central lumen 26 duringdelivery of the pledget to vessel V. Once ejected from central lumen 26,disk 42 elastically recovers its elliptical shape. Of course, inaddition to elliptical shapes, it will be evident to one of ordinaryskill in the art that disk 42 may comprise other shapes, e.g., circularor oblong, so long as disk 42 can completely occlude puncture P whendisposed therein.

In accordance with one aspect of the present invention, pledget 22 andthread 38 are made of biodegradable materials, e.g., polyglycolic acid.This permits pledget 22 and thread 38 to be resorbed and excreted fromthe body along with resorption of the autologous plug, after puncture Pand tract TR have healed. It will be evident to one of ordinary skill inthe art that, by controlling parameters such as the degree ofpolymerization and crystallization, the biodegradable material may beengineered to comprise properties that permit disk 42 to elasticallydeform when inserted into central lumen 26 during delivery, and todegrade at a predetermined rate.

Referring now to FIG. 4, an exemplary method of using device 10 of thepresent invention is described. Housing 12 of device 10 optionally maycomprise a cross-sectional area greater than that of puncture tract TR,and an introducer sheath (not shown) optionally may be used to introducedevice 10 into the puncture tract. If housing 12 is sized such that itscross-sectional area does not exceed that of the puncture tract, theautologous plug formed within central lumen 26 and extruded into thepuncture tract, as described hereinbelow, is expected to engage puncturetract TR, e.g. frictionally, via tissue rebound that decreases thediameter of the puncture tract after removal of device 10.

FIG. 4A illustrates device 10 disposed within puncture tract TR, forexample, after the introducer sheath has been removed. Pledget 22 isdisposed in the distal region of central lumen 26, and plunger 20 isdisposed proximal to pledget 22 within central lumen 26. Device 10 isinserted into puncture tract TR and distally advanced therethrough untildistal opening 18 is disposed just proximal of vessel V within punctureP. Positioning of device 10 may be confirmed by backbleed of blood Bfrom injection port 16. Specifically, when distal opening 18 is advancedto a position just proximal of vessel V, blood B enters distal opening18 and backbleeds through gap 34 and annular lumen 30, into manifold 14and out of injection port 16.

Once device 10 is properly positioned just proximal of vessel V, plunger20 is distally advanced. Because plunger 20 is disposed proximal pledget22 within central lumen 26 and the diameter of shank 23 is only slightlyless than the diameter of central lumen 26, distal advancement ofplunger 20 also urges pledget 22 into vessel V. Preferably, plunger 20contacts manifold 14 when pledget 22 has been completely advanced intovessel V. Because disk 42 of pledget 22 is elliptical, disk 42 will tendto align itself with its major axis parallel to the flow of blood, asshown in FIG. 4B.

Thereafter, plunger 20 is actuated in the proximal direction to drawblood B from vessel V into central lumen 26. Due to the presence ofapertures 32 and gap 34, blood also may be drawn into annular lumen 30and/or manifold 14. Any air within device 10 may escape therefromthrough an air vent (not shown), and/or injection port 16.

Once central lumen 26 is filled with blood, a proximal force is appliedto the proximal ends of thread 38 disposed outside of puncture tract TRto engage pledget 22 against the inner wall of vessel V, thereby sealingthe puncture tract from the vessel and providing immediate hemostasis.Thereafter, source S of a blood congealing agent, such as thrombin,fibrin and/or human factor VIII, is coupled to injection port 16, andblood congealing agent A is injected into manifold 14. From manifold 14,agent A is introduced into blood present in annular lumen 30, and intocentral lumen 26 via apertures 32 and gap 34, where it initiatesclotting of the blood therein. Due to the engagement of pledget 22against the inner wall of vessel V, the blood congealing agent will notleak into vessel V.

After a period of time, the blood within central lumen 26 solidifiesinto autologous plug PL, with thread 38 embedded therein. In a preferredembodiment, autologous plug PL comprises a substantially cylindricalrod. Autologous plug PL then may be extruded from device 10 by actuationof plunger 20 and proximal retraction of device 10 from puncture tractTR.

Once autologous plug PL is extruded from device 10, it engages complianttissue T surrounding puncture tract TR, which is expected to retract orrebound after removal of device 10, thereby establishing a compressivenormal pressure between autologous plug PL and tissue T that reduces arisk of the plug becoming dislodged into vessel V. Any extraneousportion of autologous plug PL and thread 38 that proximally protrudesfrom puncture tract TR may be excised.

Referring now to FIG. 5A, an alternative embodiment of the presentinvention is described. Unlike the previous embodiment, device 44 omitsmanifold 14 and injection port 16, and retains plunger 20, pledget 22,and thread 38. Device 44 further comprises housing 52 having inner andouter tubes 46 and 48, which form annular lumen 50 that extends alongthe length of inner tube 46. Annular lumen 50 may be fluidicallycommunicative with central lumen 52 via optional plurality of apertures54, which may be disposed through and along the axial length of innertube 46. Gap 56 is defined between the distal ends of inner and outertubes 46 and 48.

Preferably, outer tube 48 is made from a transparent polymer. In use,this permits a medical practitioner to visually confirm proper placementof device 44 just proximal to vessel V. Specifically, when device 44 isadvanced within puncture tract TR to a position just proximal of thevessel, blood backbleeds through opening 58 and gap 56 into annularlumen 50. If outer tube 48 is transparent, visual confirmation may bemade. Air within annular lumen 50 may be evacuated through an air vent(not shown) in fluid communication with annular lumen 50.

The blood congealing agent of device 44 includes matrix 60 that ispreferably biodegradable. Matrix 60 may comprise, for example, a gauze,a biologically compatible foam, and/or a spun fiber, such as a mass of aloosely spun fiber, e.g. polyglycolic acid. Matrix 60 promotescoagulation of blood upon contact and mixture therewith and optionallymay be coated with, e.g., thrombin, fibrin and/or human factor VIII.Matrix 60 may comprise optional inner lumen 62 for disposition of thread38 of pledget 22 through the matrix.

During delivery of device 44 into puncture tract TR, matrix 60 isdisposed within central lumen 52 between plunger 20 and pledget 22. Oncebackbleed of blood into annular lumen 50 confirms that device 44 ispositioned just proximal of vessel V, plunger 20 may be distallytranslated to advance pledget 22 into vessel V. This position, which maybe indicated by a marker (not shown) on shaft 23 of plunger 20,corresponds to placement of matrix 60 just proximal of gap 56.

Thereafter, plunger 20 is proximally retracted to draw blood into device44. Blood enters through opening 58 and saturates matrix 60 as it flowstherethrough into the proximal portion of central lumen 52. Blood alsomay be drawn into annular lumen 50 via gap 56, and introduced intocentral lumen 52 via apertures 54, if present. Apertures 54 preferablyare disposed along the length of inner tube 46, such that blood mayevenly distribute along the length of central lumen 52, thereby evenlypermeating matrix 60. Upon contact and mixture of the blood and thematrix, the blood congeals into an autologous plug that integratesmatrix 60 therein. The resultant autologous plug is extruded from device44 and disposed within puncture tract TR to compressively engage thesurrounding tissue, thereby preventing leakage of blood therefrom.

Referring now to FIG. 5B, an alternative embodiment of device 44 isdescribed. Housing 65 of device 64 is similar to that of the previousembodiment, except that apertures 54 are omitted from inner tube 68 ofthe present embodiment. Device 64 also comprises plunger 66, pledget 22,and flange 70 that facilitates translation of housing 65 within puncturetract TR, and actuation of plunger 66 relative to housing 65. In thepresent embodiment, plunger 66 comprises injection port 72 disposed atthe proximal end, shank 74 that is translatably disposed within centrallumen 52, and injection lumen 76 disposed therethrough. Injection port72 may comprise a coupling, such as a luer valve, that can be releasablyjoined to a source of blood congealing agent (not shown). Thus, insteadof injecting blood congealing agent into a manifold as with device 10,device 64 permits injection directly into plunger 66, therebyeliminating apertures 32 from device 10 and reserving annular lumen 50solely to provide visual confirmation of placement of device 64 relativeto vessel V. It should be noted that injection lumen 76 also may be usedas a thread lumen through which thread 38 attached to pledget 22 may beadvanced (not shown).

In yet another alternative embodiment of the present invention, innerwall 77 of inner tube 68 may be pre-coated with a blood congealingagent, e.g., thrombin, fibrin and/or human factor VIII, or lined with amatrix that is preferably biodegradable (e.g., gauze or biologicallycompatible foam). This eliminates the need to separately introduce afluid blood congealing agent into the blood isolated within centrallumen 52, thereby eliminating the need for injection lumen 76 in plunger66. Coagulation of blood further may be enhanced by contact withplatinum wires 78, or convection and conduction of heat fromthermo-resistive wires 78 disposed within inner tube 68, as shown in theinset of FIG. 5B. If thermo-resistive wires are provided, they may beproximally connected to a power source (not shown).

In a still further alternative embodiment of device 64, outer tube 48may be omitted, thereby eliminating annular lumen 50, as well as gap 56.Shown in FIG. 5C, device 80 may be provided with only a single innertube 68 having central lumen 52 in which shank 74 of plunger 66 may betranslatably disposed. In this embodiment, central lumen 52 or injectionlumen 76 of plunger 66 also may serve as a backbleed lumen through whichblood may pass for visual confirmation of proper placement of device 80proximate to vessel V. As discussed previously, injection lumen 76further may be used as a thread lumen for disposition of thread 38therethrough.

As with device 64, blood congealing agent may be introduced to the blooddrawn into central lumen 52 by injection of the blood congealing agentinto injection lumen 76, pre-coating or lining the central lumen withthe blood congealing agent, e.g., thrombin, fibrin and/or human factorVIII, or exposing the blood to platinum or thermo-resistive wires.Additional techniques will be apparent to those of skill in the art.

As shown in FIGS. 5C-5E, the blood congealing agent also may includematrix 82 that is preferably biodegradable, and which is disposed withincentral lumen 52 between plunger 66 and pledget 22. Matrix 82 maycomprise a gauze, a biologically compatible foam, and/or a spun fiber,e.g. a mass of loosely spun fiber, such as spun polyglycolic acid.Matrix 82 optionally may be coated with, e.g., thrombin, fibrin and/orhuman factor VIII. Upon contact and mixture with matrix 82, bloodcoagulates into an autologous plug, integrating the matrix and thread 38therein.

As shown in FIG. 5D, matrix 82 preferably has a cross-section thatincorporates plurality of longitudinal channels 84 and optional innerlumen 83 for disposition of thread 38 of pledget 22 therethrough.Channels 84 provide fluid communication between opening 86, disposed atthe distal end of inner tube 68, and the proximal portion of centrallumen 52. This permits blood to backbleed through matrix 82 and eitherinjection lumen 76 or central lumen 52 to provide visual confirmationthat device 80 is properly positioned just proximal to vessel V prior toactuation of plunger 66 to introduce pledget 22 within vessel V.Channels 84 also facilitate introduction and distribution of blood alongthe length of matrix 82, and into the proximal portion of central lumen52. Preferably, matrix 82 expands to a substantially circularcross-section after mixture with the blood, thereby eliminating channels84.

It will be evident to one of ordinary skill in the art that, while FIG.5D illustrates a plurality of channels disposed along the circumferenceof matrix 82, channels 84 also may include other configurations, such aslumens 86 disposed through the longitudinal length of the matrix, asshown in FIG. 5E, or a combination thereof.

Referring now to FIG. 6, a still further alternative embodiment of thepresent invention is described. Like the embodiment of FIGS. 2 and 3,device 90 comprises housing 92 having manifold 94 and injection port 96,and plunger 98 having head 100 and shank 102 disposed for axialtranslation within housing 92. Housing 92 includes inner tube 104 andouter tube 106, wherein inner tube 104 is rotatable but not axiallytranslatable relative to outer tube 106. Rotation of inner tube 104 maybe facilitated by actuator 107 coupled thereto. Annular lumen 108 isformed between inner and outer tubes 104 and 106, and is in fluidcommunication with manifold 94 and injection port 96. Annular lumen 108is in fluid communication with central lumen 110 via plurality ofapertures 112, which is disposed through and along the axial length ofinner tube 104. Gap 114 is defined between the distal ends of inner andouter tubes 104 and 106.

As in device 10, the diameter of central lumen 110 is designed to forman autologous plug therein, that engages tissue T when extruded intopuncture tract TR. Shank 102 is slightly smaller than that of centrallumen 110 and may be translated therein.

Instead of having a pledget to isolate blood from, and prevent leakageof blood congealing agent into, vessel V, device 90 includes irisclosure 118 disposed at the distal end thereof. As shown in greaterdetail in FIGS. 7 and 8, iris closure 118 comprises iris plate 120rigidly fixed to the distal end of outer tube 106, having tracks 122 andopening 124 therethrough. Iris closure 118 further comprises overlappingiris blades 126 that may be selectively actuated, as describedhereinbelow, to expose or seal opening 124. Each iris blade 126comprises distal bearing 128 and proximal bearing 130. Distal bearing128 has a non-circular cross-sectional area, e.g., square, that is keyedto iris track 122. Distal bearing 128 also has end 131, e.g., a solderball, having a diameter greater than the width of iris track 122 toprevent disengagement of distal bearing 128 from the iris track duringactuation of iris closure 118. Proximal bearing 130 is configured toextend through gap 114 and into blind slots 132 disposed in the distalend of inner tube 104.

As shown in FIGS. 7A and 8A, slots 132 radially extend through thethickness of inner tube 104 without penetrating into central lumen 110or annular lumen 108. As shown in FIGS. 7A, 8B and 8C, iris tracks 132extend from opening 124 of iris plate 120 and curve along theirrespective lengths. The cross-sectional shapes of distal bearings 128are keyed to iris tracks 122 so that actuation of distal bearings 128along the iris tracks rotates distal bearings 128 along the curve of theiris tracks (see FIG. 8C). Since iris blades 126 are rigidly affixed todistal bearings 128, rotation of the distal bearings rotates iris blades126 therewith, thereby exposing or sealing opening 124 depending on thedirection of rotation of iris plate 120 relative to slots 132, or viceversa.

In operation, to expose opening 124 from its sealed configuration shownin FIGS. 7B and 8B, inner tube 104 is rotated, e.g., in thecounter-clockwise direction relative to outer tube 106. This causesslots 132 engaged to proximal bearings 130 to impart a tangential forceto each bearing 130. Since proximal bearings 130 are rigidly affixed toiris blades 126, the tangential forces imparted to bearings 130 forcemovement of iris blades 126 and distal bearings 128 along the curve ofiris tracks 122. As illustrated in FIG. 8C, as distal bearings 128travel therealong, iris blades 126 rotate with the curve of iris tracks132, retracting the blades and exposing opening 124. Contemporaneously,proximal bearings 130 move along slots 132 in the outwardly radialdirection. Rotation of inner tube 104 relative to outer tube 106terminates when distal bearings 128 contact outer ends 134 of iristracks 122. At this point, iris blades 126 have been completelyretracted to expose opening 124.

To seal opening 124, inner tube 104 is rotated, e.g., in the clockwisedirection relative to outer tube 106. This forces distal bearings 128 tomove along the curve of iris tracks 122 in the inwardly radial directiontowards opening 124, rotating iris blades 126 therewith to seal opening124. When distal bearings 128 contact inner ends 136 of iris tracks 122,iris blades 126 have fully sealed opening 124.

While iris blades 126 are shown disposed proximal to iris plate 120 inFIGS. 6 and 7, it will be evident to one of ordinary skill in the artthat iris blades 126 also may be disposed distal to iris plate 120, withminor design modifications to proximal bearings 130. Furthermore, italso will be evident that iris blades 126 may comprise numerous shapesother than the teardrop shape illustrated in FIGS. 7B, 8B and 8C.

Referring now to FIG. 9, an exemplary method of using device 90 isdescribed. As discussed with reference to device 10, housing 92 ofdevice 90 optionally may comprise a cross-sectional area greater thanthat of puncture tract TR. Accordingly, an introducer sheath (not shown)may be used to introduce device 90 into puncture tract TR. FIG. 9Aillustrates device 90 in its delivery configuration after, for example,the introducer sheath has been removed, with iris blades 126 retractedto expose opening 124 within iris plate 120, and shank 102 of plunger 98disposed within central lumen 110 just proximal to gap 114. Thisposition may be indicated by a marker (not shown) disposed on shank 102,and permits blood to backbleed through gap 114 into annular lumen 108 tofacilitate placement of device 90 relative to vessel V.

In this delivery configuration, device 90 is inserted into puncturetract TR and distally advanced therethrough until opening 124 isdisposed just proximal to vessel V, as may be determined by observationof blood B exiting from injection port 96. In particular, when opening124 is advanced to a position just proximal to vessel V, blood B entersopening 124 and backbleeds through gap 114 and annular lumen 108, intomanifold 94 and out of injection port 96.

Once device 90 is properly positioned just proximal to vessel V, plunger98 is actuated in the proximal direction to draw blood B from vessel Vinto central lumen 110, as seen in FIG. 9C. Due to the presence ofapertures 112 and gap 114, blood also may be drawn into annular lumen108 and/or manifold 94. Any air within device 90 may be expelledtherefrom through an air vent (not shown) and/or injection port 96.

Once central lumen 110 is filled with blood B, actuator 107 may be usedto rotate inner tube 104 relative to outer tube 106, actuating irisblades 126 to seal opening 124 in the manner discussed above.

Source S of blood congealing agent is coupled to injection port 96, andblood congealing agent A is injected into manifold 94. From manifold 94,blood congealing agent A mixes with blood present in annular lumen 108and into central lumen 110, via apertures 112 and gap 114, initiatingclotting of the blood. Since opening 124 is sealed, thereby isolatingthe blood within device 90, blood congealing agent A will not leak intovessel V. After a period of time, the blood within lumen 110 solidifiesinto autologous plug PL. Accordingly, in a preferred embodiment,autologous plug PL comprises a cylindrical rod.

Inner tube 104 then is rotated relative to outer tube 106 to exposeopening 124 in the manner discussed above. Autologous plug PL isextruded from central lumen 110 by holding plunger 98 stationary ashousing 92 is proximally retracted so that plunger 98 urges autologousplug PL out of lumen 110, as seen in FIG. 9D. Any blood contiguouslycoagulated with autologous plug PL, such as that potentially disposedwithin annular lumen 108, apertures 112, and gap 114, is expected toshear off when plug PL is extruded out of device 90.

Once autologous plug PL is extruded from device 90, it engages complianttissue T surrounding puncture tract TR, which is expected to retract orrebound after removal of device 90, thereby establishing a compressivenormal pressure between autologous plug PL and tissue T that reduces arisk of the plug becoming dislodged into vessel V. Any extraneousportion of autologous plug PL that proximally protrudes from puncturetract TR may be excised.

Referring now to FIG. 10A, a further is alternative embodiment of thepresent invention is described. Device 140 is similar to the precedingembodiment, except manifold 94 and apertures 112 have been omitted.Device 140 includes iris closure 142 having iris blades 146 operablyengaged to iris plate 148, which includes opening 150 and a plurality ofiris tracks similar to those described in FIGS. 7 and 8. Iris closure142 is disposed on the distal end of housing 152 having inner tube 154,outer tube 156 which is rotatable but not axially translatable relativeto inner tube 154, and annular lumen 158 disposed therebetween. Operatedin the same manner as described previously with reference to FIGS. 7 and8, rotation of inner tube 154, which may be facilitated by actuator 159coupled thereto, actuates iris closure 142 to expose or seal opening150, depending on the direction of rotation of inner tube 154 relativeto outer tube 156. The distal ends of inner and outer tubes 154 and 156define gap 160, which provides fluid communication among opening 150,annular lumen 158 and central lumen 162 of inner tube 154.

Preferably, outer tube 156 is made from a transparent polymer tofacilitate visual confirmation of the advancement of device 140 to aposition just proximal to vessel V in puncture tract TR. In use, whenopening 150 is disposed just proximal to vessel V, blood backbleedsthrough opening 150 and gap 160 into annular lumen 158. Air withinannular lumen 158 may be evacuated through an air vent (not shown) influid communication therewith.

Device 140 also comprises plunger 164 and flange 166 that facilitatesinsertion of housing 152 within puncture tract TR. In the presentembodiment, plunger 164 comprises injection port 168 disposed at theproximal end, shank 170 that is configured to be translatably disposedwithin central lumen 162, and injection lumen 172 disposed therethrough.Injection port 168 may comprise a coupling, such as a luer valve, thatcan be releasably joined to a source of blood congealing agent (notshown). Accordingly, instead of injecting blood congealing agent into amanifold as in the preceding embodiment, device 140 permits injectiondirectly into plunger 164, thereby eliminating apertures 112 from device90 and reserving annular lumen 158 solely to provide visual confirmationof the disposition of device 140 just proximal to vessel V.

In an alternative embodiment of device 140, inner wall 174 may bepre-coated with a blood congealing agent, e.g., thrombin, fibrin and/orhuman factor VIII, or lined with a matrix (e.g., gauze, spun fiber orbiologically compatible foam). This eliminates the need to introduce ablood congealing agent into the blood isolated within central lumen 162,thereby eliminating the need for injection lumen 172 in plunger 164.Coagulation of blood further may be enhanced by contact with platinumwires 176, or convection and conduction of heat from thermo-resistivewires 176 disposed within inner tube 154, as shown in the inset of FIG.10A. Alternatively, central lumen 162 may be pre-filled with a matrix topromote coagulation of blood upon contact and mixture therewith, asdescribed hereinabove with respect to FIGS. 5A and 5C-5E.

In an alternative embodiment of device 140, annular lumen 158 and gap160 may be omitted. Shown in FIG. 10B, device 178 includes inner andouter tubes 154 and 156 adjacently disposed, and iris closure 142operably coupled to the distal ends thereof. Central lumen 162 orinjection lumen 172 of plunger 164 may serve as a backbleed lumenthrough which blood may pass for visual confirmation of proper placementof device 178 proximate vessel V.

As in device 140, blood congealing agent may be introduced to the blooddrawn into central lumen 162 by injection of the blood congealing agentinto injection lumen 172, pre-coating or lining the central lumen withthe blood congealing agent, e.g., thrombin, fibrin, human factor VIII,and/or a matrix (e.g., gauze, spun fiber or biologically compatiblefoam), or exposing the blood to platinum or thermo-resistive wires.Alternatively, central lumen 162 may be pre-filled with a matrix topromote coagulation of blood upon contact and mixture therewith, asdescribed hereinabove with respect to FIGS. 5A and 5C-5E.

Referring now to FIG. 11, another embodiment of the apparatus of thepresent invention is described. Device 180 is similar to devices 90 and140 respectively of FIGS. 6-8 and 10, except that the iris closures ofthose embodiments are replaced by alignment closure 182. Affixed to thedistal end of inner tube 184 is proximal plate 186 having through-wallslots 188. Affixed to the distal end of outer tube 190 is distal plate192 having through-wall slots 194 that have a shape identical to that ofslots 188. When slots 188 and 194 are aligned, as shown in FIGS. 11 and12A, blood may be drawn into central lumen 196 disposed through thelength of inner tube 184, or an autologous plug may be extrudedtherethrough. When inner tube 184 is rotated relative to outer tube 190,distal and proximal plates 192 and 186 respectively obscure slots 188and 194, as shown in FIG. 12B. In this configuration, blood is isolatedwithin central lumen 196, and blood congealing agent may be supplied tothe isolated blood to initiate clotting thereof.

Optional annular lumen 198 is defined by inner and outer tubes 184 and190, and is in fluid communication with central lumen 196 via optionalapertures 200 circumferentially disposed through inner tube 184 justproximal to proximal plate 186. To determine if device 180 has beenproperly positioned just proximal to vessel V, blood may backbleedthrough aligned slots 188 and 194 and apertures 200 into annular lumen198. Accordingly, during delivery of device 180 into a puncture tract,the maximum distal position to which plunger 202 may be advanced withincentral lumen 196 is a position just proximal to apertures 200. Thisposition may be indicated by a marker (not shown) disposed on plunger202. As will be apparent to those of skill in the art, rather thanhaving annular lumen 198 for backbleed indication, central lumen 196 ofdevice 180 may serve as a backbleed lumen. Alternatively, a lumen may beprovided through plunger 202 for backbleed indication and/or injectionof a blood congealing agent, as described with respect to FIGS. 5B-5Cand 10A-10B.

In operation, device 180 is inserted into puncture tract TR with slots188 and 194 aligned, and plunger 202 disposed just proximal to apertures200. Device 180 then is advanced to a position just proximal to vesselV. This position may be visually confirmed by observation of blood thatbackbleeds through slots 188 and 194 and, for example, apertures 200into annular lumen 198 and/or out of a proximal injection port (notshown) in fluid communication with annular lumen 198. Plunger 202 thenmay be proximally retracted within central lumen 196 to draw bloodtherein from vessel V. Once central lumen 196 is filled, inner tube 184is rotated relative to outer tube 190 to obscure slots 188 and 194,thereby isolating the drawn blood within device 180. Clotting of theblood may be initiated by introducing blood congealing agent intocentral lumen 196. Alternatively, the inner wall of inner tube 184 maybe pre-coated with a blood congealing agent, e.g., thrombin, fibrinand/or human factor VIII, lined with a matrix (e.g., gauze, spun fiberor biologically compatible foam), or comprise platinum orthermo-resistive wires that are exposed to the blood therein. When theblood has solidified to form autologous plug PL, inner tube 184 isrotated relative to outer tube 190 to align slots 188 and 194. Plunger202 is held stationary as device 180 is proximally retracted frompuncture tract TR, thereby urging autologous plug PL from central lumen196 through slots 188 and 194. Once disposed within puncture tract TR,the segments of the autologous plug that had been extruded through slots188 and 194 are urged together due to the compressive pressure of tissueT surrounding the puncture tract. In this manner, puncture tract TR issealed from leakage of blood.

Referring now to FIG. 13, yet another alternative embodiment of thepresent invention is described. Device 210 includes housing 212 havinginner and outer tubes 214 and 216, which form annular lumen 218therebetween. Device 210 also includes plunger 220 translatably disposedwithin central lumen 222, and membrane 224, which is preferablybiodegradable. Membrane 224 is disposed over distal opening 226 ofcentral lumen 222 and is releasably attached to inner wall 228 of innertube 214 so that membrane 224 forms a sock within which is disposedblood congealing agent 230. Membrane 224 is preferably attached to innerwall 228 with a biodegradable adhesive or suture that permits themembrane to be sheared from inner wall 228 when an axial force isapplied to blood congealing agent 230.

Membrane 224 is permeable to blood but impermeable to blood congealingagent 230, thereby permitting blood to be introduced into central lumen222 and yet isolating the mixture of blood and blood congealing agentfrom vessel V. Selective permeability may be achieved, for example, byincorporating pores of a predetermined size within membrane 224. Thus,for example, the pores preferably have a cross-sectional dimensionlarger than the diameter of blood cells, but smaller than the diameteror cross-sectional dimension of the blood congealing agent, which alsopreferably may be provided with a predetermined size. Blood cellstypically have a diameter of about 60 μm. A pore size greater than about60 μm is therefore preferred.

Preferably, blood congealing agent 230 comprises a biodegradable matrixto promote coagulation of blood upon contact and mixture therewith, asdescribed hereinabove with respect to FIGS. 5A and 5C-5E. Alternatively,blood congealing agent 230 also may comprise powder of a bloodcongealing substance, such as polyglycolic acid, fibrin, thrombin and/orhuman factor VIII.

Outer tube 216 preferably is made from a transparent polymer to permitobservation of blood that backbleeds into annular lumen 218 when device210 is disposed just proximal to vessel V. This provides a medicalpractitioner with visual confirmation of proper placement of device 210within puncture tract TR. Optionally, inner tube 214 also may compriseapertures 232 disposed along the length thereof. Apertures 232 providefluid communication between annular lumen 218 and central lumen 222.During proximal retraction of plunger 220, blood may be drawn throughapertures 232 and blood permeable membrane 224 into central lumen 222 tomore evenly distribute the blood along the length of central lumen 222and to evenly permeate blood congealing agent 230.

In operation, device 210 is introduced into puncture tract TR withplunger 220 disposed within central lumen 222 just proximal to bloodcongealing agent 230. Device 210 is distally translated along thepuncture tract until backbleeding, e.g. through annular lumen 218,indicates that the device is properly positioned just proximal to vesselV. Plunger 220 then is actuated in the proximal direction to draw bloodinto central lumen 222 through membrane 224, covering distal opening226, as well as apertures 232, if present. Contact and mixture withblood congealing agent 230 coagulates the blood into an autologous plug,integrating blood congealing agent 230 and membrane 224 therein. Whenplunger 220 is translated in the distal direction to extrude the formedautologous plug from central lumen 222, the distal force transmitted tothe adhesive or suture binding membrane 224 to inner wall 228 shearsmembrane 224 therefrom. Disposed within puncture tract TR, theautologous plug engages tissue T surrounding the puncture tract toprevent blood leakage from vessel V.

In an alternative embodiment of device 210, outer tube 216 and apertures232 may be omitted, thereby eliminating annular lumen 218. For backbleedindication to facilitate visual confirmation of the placement of thepresent device just proximal to vessel V, plunger 220 may be providedwith an injection lumen like that described with respect to FIGS. 5B-5Cand 10A-10B.

While preferred illustrative embodiments of the invention are describedabove, it will be apparent to one skilled in the art that variouschanges and modifications may be made therein without departing from theinvention. For example, shorter autologous plugs may be formed that onlycover a portion of the length of the puncture tract. Furthermore,various blood congealing agents described hereinabove and known to thosein the art may be used in combination in a single embodiment. Theappended claims are intended to cover all such changes and modificationsthat fall within the true spirit and scope of the invention.

1. A device for sealing a puncture tract by forming and extruding anautologous plug within the puncture tract, the device comprising: ahousing having a lumen adapted to mix a volume of blood with a bloodcongealing agent; a selectively closable iris cooperating with the lumenof the housing, the selectively closable iris is configured to beinserted into the puncture tract and to isolate the mixture of thevolume of blood and the blood congealing agent from the vessel duringformation of the autologous plug; and a plunger disposed for translationwithin the lumen to extrude the autologous plug formed within the lumen.2. The device of claim 1, wherein the housing comprises a second lumento facilitate placement of a distal end of the device.
 3. The device ofclaim 2, wherein the second lumen is disposed within the plunger.
 4. Thedevice of claim 1, wherein the autologous plug formed in the lumen has alength and a form factor that causes the autologous plug to engagetissue surrounding the puncture tract after ejection by the plunger intothe puncture tract.
 5. The device of claim 1, wherein the selectivelyclosable iris comprises a plate having a plurality of tracks and anopening disposed therethrough, and a plurality of blades operablyengaged to the plurality of tracks.
 6. The device of claim 1, whereinthe closure element comprises first and second plates, each of the firstand second plates having a plurality of through-wall slots, the firstand second plates being relatively rotatable to selectively align thepluralities of through-wall slots.
 7. The device of claim 1, wherein theclosure element comprises a membrane that is permeable to blood andimpermeable to the blood congealing agent.
 8. The device of claim 1,wherein the blood congealing agent is pre-disposed within the lumen. 9.The device of claim 8, wherein the blood congealing agent is coated ontoan interior surface of the lumen.
 10. The device of claim 1, wherein theblood congealing agent is introduced into the lumen subsequent toactuation of the closure element.
 11. The device of claim 10, whereinthe blood congealing agent comprises a platinum wire.
 12. The device ofclaim 11, wherein the blood congealing agent comprises athermo-resistive wire.
 13. The device of claim 1, wherein the bloodcongealing agent is chosen from the group consisting of thrombin,fibrin, human factor VIII, and combinations thereof.
 14. The device ofclaim 1, wherein the blood congealing agent comprises a matrix.
 15. Thedevice of claim 14, wherein the matrix is chosen from the groupconsisting of gauze, biocompatible foam, and spun fiber.
 16. The deviceof claim 14, wherein the matrix is biodegradable.
 17. The device ofclaim 14, wherein the matrix comprises at least one channel disposedtherethrough.